Circular knitting machine



1954 c. F. MILLER v 2,696,720

CIRCULAR KNITTING MACHINE IN VEN TOR.

47702/VEV United States Patent Office 2,696,720 Patented Dec. 14, 1954CIRCULAR KNITTING MACHINE Charles F. Miller, Philadelphia, Pa.,assignor, by mesue assignments, to Jacquard Knitting Machine Co., Inc.,a corporation of Pennsylvania Application July 20, 1949, Serial No.105,728

6 Claims. (Cl. 6 620) This invention relates to knitting machines inwhich the positions of one or more cams must be changed from time totime in a manner to change its action on the stitch-forming elementssubject to it, and in which the change must be made while the knittingoperations of the machine continue. This is a characteristic of circularknitting machines as is well known, and for brevity I shall referhereafter to circular machines substantially only. It is to beunderstood however that any form of knitting machine in which a cam isto be shifted While in the midst of a field of stitch-forming elements,is to be regarded as an equivalent of a circular machine for the presentpurposes. The invention is applicable not only" to cams for operatingneedles but also to cams for operating the other devices which onoccasion are used to take part in the formation of stitches in knittingmachines, e. g. sinkers, pressers, warp-yarn guides, etc., and jacks foroperating any of the foregoing, all of which are here classed asstitch-forming elements.

When a cam is shifted in the midst of a field of needles or otherstitch-forming elements that are actuatable by the cam, there is dangerthat one or more of the stitchforming elements will be brought to orleft in a midposition as it were, where it will be struck later anddamaged by the same or another cam. Ordinarily it is necessary to takespecial precautions to avoid this, and various expedients have beenresorted to heretofore. For example, arrangements have been made foroperating the knitting machine unusually slowly while the change isbeing made, so that the change is effected rapidly relative to the speedof the cams along the needle bank. Again, needles have been omitted fromthe machine at one or more places in a needle bed and arrangements madeto shift the cams at such places, i. e. while out of engagement withneedles. This permits cams to be shifted without danger of accident, butresults in an unknitted stripe or stripes in the fabric, runninglengthwise of the fabric. Still again, it has been proposed to use atone or more places in a needle bed, some needles with long butts andother needles with short butts, and divide each cam that is to beshifted into a long butt section and a short butt section. Byappropriate placements of the groups of needles and appropriatemanipulation of the cam sections, the cam as a whole can be shifted fromone position to another without danger.

The present invention provides a cam-shifting arrangement which issomewhat simpler mechanically than the latter expedient, and which doesnot leave an unknittcd stripe in the fabric, and which need not requirethe machine to be slowed down, at least ordinarily.

Briefly this is accomplished by providing, at one or more places in thebank of stitch-forming elements, one or a group of stitch-formingelements (usually three or four are suflicient) which are so constructedthat they are not affected by the cam or cams to be shifted, but socontrolled as to knit. To the latter end special mechanism, which may bea cam or cams, may be and preferably is provided to actuate thesestitch-forming elements (which I call the special stitch-formingelements) through at least such a part of their operating cycles as maybe necessary in view of the fact that they are unaffected by theshiftable cams. The mechanisms which control the shifting of theshiftable cams are then arranged tomake the shifts, when needed, whilethe shiftable cams are passing the special stitch-forming element orgroup of special stitch-forming elements. Obviously, a-shiftable cam canbe moved, at'such a place, from one position to 'anotherwithout dangerof mis'placer'nent of a stitch-forming element, and at the same time nounknitted stripe is left in the fabric. In order that the specialstitch-forming elements may not be affected by the shiftable cam orcams, preferably the special stitchforming elements are wholly devoid ofbutts at the path of the shiftable cam or cams, and are passed throughtheir knitting motions by butts located outside the paths of the camswhich actuate the, say, remaining and major number of thes'titch-forming elements of the bank. If however it is desired for anyreason that the special stitch-forming elements have butts in the pathof some cam operating the remaining needles, usually some cam of thatpath can be cut in such a manner as to permit the presence of thedesired butts.

The accompanying drawings illustrate examples of the foregoing asapplied to the actuation of needles, and from which its application toother forms of stitch-forming elements will be understood. In thosedrawings Fig. 1 is a diagrammatic elevation of a two-feed circularknitting machine. Fig. 2 is a diagrammatic illustration at one of thefeeds of the machine of Fig. l as viewed from within the bank ofneedles. Fig. 3 is a similar illustration at the other of the two feedsof the machine of Fig. 1. Fig. 4 is a diagrammatic illustration of thecamming' system of another embodiment of the invention, and Fig. 5illustrates sectionally the needle and cam relations of Fig. 4. Fig. 6is a view similar to Fig. 2 or Fig. 3 but showing an arrangement inwhich the special stitch-forming elements have butts in the same race asa cam that is to be shifted.

The machine shown in Fig. l is a two-feed dial-andcylindersliding-needle knitting machine having the usual arrangement of needlecylinder 1 and needle dial at 2. As will be understood, much of themechanism of the machine, and even essential mechanism, has been omittedfrom Fig. 1 for clarity since the omitted mechanism forms no part of theinvention. A cam ring 3 carries the cams which cause the cylinderneedles to perform their knitting operations, e. g. in the presentinstance project and retract the cylinder needles, and a cam cap on thedial at 2 carries the cams which actuate the dial needles, as iscustomary in this form of machine. The needle beds and the cam carriersare mounted, directly or indirectly, on the base 4- of the machine whichis carried by the legs 5. In the present instance the needle beds 1 and2 are stationary andthe cam ring and dial cam cap rotate, synchronously,but it will be understood that the invention is as applicable tomachines in which the needle bed or beds rotate and the cam carriers arestationary. Also it is to be understood, and will become obvious as thisdescription proceeds, that the invention is not limited to dial andcylinder machines, but is applicable to other forms of machines also, e.g. machines having only a single needle bed, links-anddinks machines,etc.

The cam arrangements for the cylinder needles at the two feeds of thismachine of Fig. lare shown in Figs.- 2 and 3 respectively, and asrepresentative ofarrangements that may be made to secure variation inthe knit ting (i. e. to produce a patterned or fancy effect cloth, orsome desired construction of the cloth) some of the cylinder needles 6are given long operating, i. e. camen'gagin-g, butts while the remainderof the cylinder needles 7 (excepting the special needles referred toagain) are given shorter operating butts. The number of each form ofcylinder needle and their distribution is determined, as heretofore, bythe effect to be produced. Likewise the manner in which the dial needlesare actuated is not material to the invention, and can be determined bythe effect to be produced; it may be assumed for the present purposesthat alternate dial needles are proje'cte'd and retracted to knit at onefeed and that the intermediate dialneedles are projected and retractedto knit at the other feed.

'The needles- 6 and 7 are to produce patterns or other fancy effectsinthe fabric and hence constitute the major number: of the needles orthe cylinder needle bank, for example all exce t for the few specialneedles referred to: again hereafter. A earn race 8- ecnnects' the exitor stitch eamend; ot'the teed otEigJwittrthe: entranceend.

of the feed of Fig. 2, and a similar race 8a connects the exit or stitchcam end of the Fig. 2 feed with the entrance end of the Fig. 3 feed. Inthe present instance the long and short butts of the needles 6 and 7 areused to cause the cylinder needles to form tuck stitches in lieu of knitstitches on occasion and at certain places in the fabric; it will beunderstood from the foregoing however that the invention is not limitedto a tuck and knit stitch variation, but is applicable to any sort ofvariation of knitting operations that may be desired. To produce thisknit and tuck variation at the Fig. 2 feed, there is provided at thisfeed a cam 9 suitable to raise both long and short butt needles 6 and 7to a height where the loops on the needles drop behind the needlelatches (assuming latch needles) and hence produce knit stitches. A cam11, suitable to engage with the long butts of needles 6 but so thin thatit passes the short butts of the needles 7 without striking them,serves, when active, to raise the long butt needles from the race 8level to the cam 9. Below the cam 9 a race 12 is provided by a cam 13which is capable of raising any cylinder needle the butt of which entersthe race 12, to such a height that the needle latch is opened, but nothigh enough to clear the old loops below the needle latches, and hencecause tuck stitches. Back of the cams 9 and 13 the butt-engaging surface14 of a stitch-cam 16 retracts both the long and short butt needlessufllciently to cast-off, and from 15 below the stitch cam 16 theneedles may be raised to the rest race 8a as is customary.

Between the outlet end of rest race 8 and the cams 9 and 13 is provideda gate cam or pair of cams 17 and 18 coupled together for simultaneousmovement lengthwise of the needles. These cams 17 and 18 are thickenough, in the arrangement of Fig. 2, to engage the butts 'of allneedles of the cylinder bank and are so shaped as to cause the butts ofneedles coming to them to pass between them, regardless of whether theyare in their upper or their lower positions. Accordingly when this gatecam or cam pair 1718 is in its lower position, shown in full lines inFig. 2, all needles coming from the rest race 8 are directed to the thincam 11, with the result that the long butt needles 6 pass over the cam 9and hence form knit stitches, and the short butt needles -7 pass intothe race 12 and hence form tuck stitches at this feed of Fig. 2. On theother hand when the gate cam or cam pair 1718 is in the upper position,indicated by broken lines in Fig. 2, all the needles leaving the race 8,both long and short butt, are raised by the cam 17 to lengthwisepositions where all of them pass over the cam 9 and hence all form knitstitches at the feed of Fig. 2. Hence the gate cam 1718 is able todirect needles to the race 12 or to the race above the cam 9 as theoperator of the machine may desire. These two races constitute, as itwere, alternative races for the butts of the stitch-forming elements.

The camming at the feed of Fig. 3 is the reverse of that at Fig. 2, asit were. That is to say, the outlet end of rest race 8a has cam surfaces19 and 20 which deliver all needles at such a height that (except forthe gate cam) all needles will pass onto the cam 22 which correspondsgenerally to cam 9 of Fig. 2, i. e. is thick enough to engage both thelong and short butts and raise needles to knitting positions. Below thiscam 22 is a race 24, the lower cam 25 of which is thick enough to engageboth the long butts and the short butts, and is capable of raising theneedles to tuck stitch positions at this feed of Fig. 3. Back of cams 22and 25, the butt-engaging surface 26 of stitch cam 28 retracts all theneedles to cast-off position, and from 27 below it the needles may beraised to their rest positions in race 8, as is customary.

Between the outlet of race 8a and the cams 22 and 25 is provided a gatecam or pair of cams 29 and 30 coupled together for simultaneous movementlengthwise of the needles. These earns 29 and 30 are thin cams (or atleast 29 is a thin cam) so that the short butts of needles 7 can passthe gate cam 2930 without being engaged and repositioned by it, but thelong butts of the needles 6 are engageable by the gate cam and hencerepositionable by it, and caused to pass between the two cams 29 and 30regardless of whether the gate is in its upper or its lower position.Accordingly when this gate cam or cam pair 2930 is in its lowerposition, shown in full lines in Fig. 3, the short butt needles 7 passover the cam 22 and form knit stitches, but the long butt needles 6 passto the race 24 and hence form tuck stitches at the feedv of Fig. 3. Onthe other hand, when the gate cam or cam pair 29--30 is in its upperposition, shown by broken lines in Fig. 3, all the needles are directedonto the cam 22, and hence all the needles form knit stitches at thefeed of Fig. 3.

It follows therefore that by raising or lowering the gate earns, thewhole of the face of the fabric that is made by the cylinder needles 6and 7 may be composed of knit stitches, or may be composed of a mixtureor mixtures of knit and tuck stitches, or may be composed in part of amixture of knit and tuck stitches and in part of knit stitches alone.

A conventional mechanism for shifting the gate cams is shown. That is,the cams 17 and 18 are mounted on a vertical rod 32 that is slideablelengthwise in the cam cylinder 3 and which is provided with a horizontalpin that rests in a sinusoidal slot 35 in the edge of a disc 34. Thedisc 34 is rotatable on the upper edge of the cam cylinder 34 and hasattached to it a star wheel or series of radially projecting arms 36. Abob-pin 38 having a head 37 is raised and lowered under the control of apattern chain 40 which is advanced around a pulley at 42. Normally thehead 37 is below the path of the star wheel 36, as shown in Fig. 1, andthus has no effect on the gate cam 17-18, but whenever the pattern 40raises the bob pin 38, the head 37 is placed in the path of the starwheel 36 so that as the cam cylinder 3 rotates the star wheel is causedto strike the head and thereby turned one step. If the gate cam 1718 isin its lower position, this action moves it to its upper broken-lineposition; if it is in its upper position, the action restores the gatecam to its lower full-line position. The gate cam or cam pair 2930 ismounted and shifted similarly, by the same bob pin 38, as will berecognized from Figs. 3 and 1. If desired, the pattern chain 40 may beadvanced at such a rate or at such times that the gate cams of the twofeids are shifted alike, or shifted independently of each ot er.

in the present instance the present invention is applied to permit theshifting of the gate cams without endangering the needles. To this endthe cylinder needle bed 1 is provided with a few, say four, specialneedles 44. These are located adjacent the bob pin 38; morespecifically, at the part of the needle bed whereat the shifting of thegate cams occur under the direction of the bob pin 38. These needleshave no butts within the path of any of the cams of the regular camsystem previously described. Accordingly either gate cam can be shifted,either up or down, while passing over this group of special needles 44without danger of leaving a needle misplaced in a position where it canbe struck later by a cam head-on and thereby damaged. Below the regularcam paths, or speaking more generally, displaced lengthwise of theneedles, the special needles 44 are provided with butts 45 and two cams46 are added to the cam ring 3, one at each feed, to engage these buttsand raise the special needles to clearing positions at the respectiveyarn feeds. Accordingly the special needles 44 take yarn from whicheverfeed is passing at the moment, and being retracted form knit stitches. Astitch cam 47 is added to the cam ring at each feed, at an appropriateplace back of the adjacent raising cam 46, to retract the specialneedles to complete their stitches, acting on the butts 45 of thespecial needles. By this arrangement accordingly the gate cams can beshifted safely without the occurrence of an unknitted strip of fabric atthe shifting position, and without any need of slowing the speed ofrotation of the cams when a gate cam is to be shifted either up or down,provided the group of the special needles 44 is sufficiently large topermit the shift to occur while the gate cam is passing over the group.

The modification of this arrangement shown in Fig. 6 permits theelimination of the special stitch cams 47 for example. In thismodification each of the special needles 48 is provided with a butt 49so disposed as to run in the regular cam races, but which is shorterthan the short butts of the needles 7. The regular cams such as 9 and16, 17, 18, etc., may be as described with reference to Fig. 2, andthick enough to engage and act on the extra short butts 49, except thatthe cam 11 is continued thin so as to act on only the long butts of theneedles 6 and the shiftable cam, e. g. 18, and if necessary the lowerend of the guard cam which is above the needle projecting cam 9, aremade so thin that the extra short butts 49 are outside the paths ofthese latter cams, i. e. these cams pass them without engagement; or tothis end they may be cut back or thinned at their lower portions, say tothe lines 50, so that the e *tra short butts 49 can pass them withoutengagement under all conditions. The projecting cam 51 for the specialneedles 48 then is arranged to, say, raise the special needles so thattheir butts 49 pass from the race 8 onto the cam 9. This cam 51,similarly to the cams 46, is displaced, lengthwise of the needles, fromthe regular cams 9, 11, 17, 18, etc., i. e. in the present instance isplaced at a lower level than the regular cams. With such an organizationthe regular stitch cam 16 serves to retract the special needles tocomplete their stitches, thereby eliminating the need for the specialstitch cam 47 of Fig. 2. Other possible variations along this line areobvious.

Speaking generally, any arrangement whereby the special needles (orwhatever the stitch-forming elements may be) are caused to performknitting operations in dependently of the shiftable cam or cams, issufficient for the present purposes. This fact is further illustrated bythe modification shown in Figs. 4 and 5. Here the special needles 52 areprovided with butts 53 so placed as to run in the regular cam races andbe actuated by the regular cams other than the shiftable cams, but whichare longer than the butts of any of the other needles, speakinggenerally. A cam 54 is provided to act on the butts 53 to project thespecial needles 52 to, say, knitting position, but which is too thin toengage with the butts of the other needles. As indicated, this cam 54can be placed between the Wall of the cam cylinder and a shiftable cam55 for the regular needles 56. The shiftable cam 55 is so placed as toact on the butts of the regular needles 56, but in no position able toengage the butts of the special needles 52; e. g. all the positions ofthe shiftable cam 55 may be below the position of the special needle cam54, as indicated in Figs. 4 and 5. It will be evident that with thisconstruction also the shiftable cam 55 can be shifted in positionwithout danger to the needles, providing the group of special needles 52is sufficiently large. A stitch cam for all the needles is shown at 57,and dial needles at 58.

It will be understood that my invention is not limited to the particularconstructions, details and operations shown in the drawings anddescribed above, except as appears hereafter in the claims, and that theclaims are intended to include equivalents of the elements named inthem, as well as those elements themselves.

I claim:

1. In a circular knitting machine, a bank of stitchforming elements, acam system to actuate said stitchforming elements, said system providingat least two alternative races for butts on elements of said bank andincluding a gate cam shiftable to direct said butts to one of said racesor the other, and mechanism to shift said gate cam from one of itspositions to the other While the gate cam is passing a particular partof said bank, characterized by the fact that at least one stitch-formingelement, devoid of a butt within any path of said gate cam, is providedat said particular part of the bank, and a cam is provided, displacedfrom the remainder of the cam system substantially lengthwise of saidelements and angularly in about the same position as said gate cam, toproject the said at least one stitch-forming element to initiateknitting operations.

2. A circular knitting machine having a bank of stitchforming elements,a cam system including a cam to actuate a major number of thestitch-forming elements of said bank through at least a portion of eachof respective stitch-forming cycles thereof and which is shiftable inposition to change its action on said stitch-forrn ing elements, andmechanism to shift said cam while the cam is passing a particular partof the bank, characterized by the fact that at least one stitchformingelement is provided at said part of the bank which is devoid of a buttthat is within a path of said shiftable cam, and mechanism is providedto act on the said at least one stitchforming element at said particularpart of the bank where said mechanism acts on said shiftable cam, tocause said at least one stitch-forming element to perform knittingoperations.

3. The subject matter of claim 2 characterized by the fact that saidsecond mentioned mechanism is a special cam.

4. The subject matter of claim 2 characterized by the fact that saidsecond mentioned mechanism is a cam which is displaced from saidshiftable cam lengthwise of the stitch-forming elements.

5. The subject matter of claim 2 characterized by the fact that saidsecond mentioned mechanism is a cam which is located angularly at aboutthe same position as said shiftable cam, but which is displaced fromsaid shiftable cam in a direction substantially at right angles to saidat least one stitch-forming element.

6. The subject matter of claim 2 characterized by the fact that said atleast one stitch-forming element has a butt that is adjacent to butoutside the path of said shiftable cam, and said second mentionedmechanism comprises a cam of said cam system that is operable on saidbutt.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 582,431 Nye May 11, 1897 649,021 Wardwell May 8, 1900 822,564Wheeler June 5, 1906 1,200,451 Ballard Oct. 10, 1916 1,236,189 LomaxAug. 7, 1917 1,858,469 Sirmay May 17, 1932 1,971,581 Schuknecht Aug. 28,1934 2,204,417 Lawson June 11, 1940

